Securities (Summary Of Maturities, Amortized Cost And Estimated Fair Values Of Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Available-for-sale Securities [Abstract]
Due in one year or less, Amortized Cost	$ 46,461
Due from one to five years, Amortized Cost	82,524
Due from five to ten years, Amortized Cost	33,110
Due after ten years, Amortized Cost	163,165
Equity securities, Amortized Cost	137
Total Amortized Cost	325,397	$ 267,105	$ 255,578
Due in one year or less, Estimated Fair Value	46,984
Due from one to five years, Estimated Fair Value	83,284
Due from five to ten years, Estimated Fair Value	33,119
Due after ten years, Estimated Fair Value	165,202
Equity securities, Estimated Fair Value	137
Total Estimated Fair Value	$ 328,726